Male hypogonadism

  1. FSH
    Has effects on the tubules of the testes to form sperm
  2. LH
    Has effects on Leydig cells which form testosterone & nourish the sperm.
  3. Which tests do you order to diagnose male hypogonadism?
    TOTAL and BIOAVAILABLE (bound - not as accurate), free if necessary. (I think)  Also get an LH level, FSH level and prolactin (elavated prolactin performs negative feedback on GnRH)
  4. Primary hypogonadism lab values
    • Low testosterone
    • High-normal to High LH and FSH
    • (Problem is with testes not producing)
  5. Secondary hypogonadism lab values
    • Low testosterone
    • Normal to low LH and FSH
    • (problem is in the pituitary or hypothalamus)
  6. Primary hypogonadism causes
    • Klinefelter's syndrome & other (mostly congenital) issues
    • Drugs, radiation, mumps, chronic disease (HIV, etc.)
  7. Eunuchoidism
    Male hypogonadism that results in deficient secondary sex-characteristics (high-pitched voice, lack of hair growth, arm span > high by 5 cm and long legs with shorter torso.
  8. Klinefelter's
    • Male with extra X-chromosome
    • Low amounts of inhibin are produced in testes so it doesn't feed back appropriately & leads to increased levels of LH and FSH with low testosterone & high estradiol
    • Tall, breast development, small testes, slightly feminized physique w/ mildly impaired IQ.
    • Diagnose with buccal smear-looking for barr bodies
    • No trx. listed - testosterone after puberty?
  9. Secondary hypogonadism causes
    • Kallman's syndrome (lack of smell)
    • Idiopathic hypogonadotropic hypogonadism w/ retardation
    • Abnormal beta-subunit of LH or FSH
    • Sarcoidosis, drugs, alcohol, etc.
  10. Tests for hypogonadism
    • Serum testosterone - 8:00 am
    • Serum FSH & LH w/ prolactin
    • Peripheral leukocyte karyotype (Klinefelter's)
  11. Treatment
    • Testosterone replacement (not for people w/ potential reversibility because you can suppress their ability to make their own testosterone)
    • Treat underlying disease
  12. Measuring injectable steroids
    Measure midway between injections
  13. Measure gel steroid levels
    After one month
  14. Measure oral steroids
    After administering 3-5 hours
  15. PSA levels
    Rise with androgen therapy but should remain within the reference range.  Maximal increase in prostate volume occurs 3 mos after initiation of trx.
  16. Polycythemia
    Seen most commonly with injectable steroids
  17. Liver disease
    Alkylated oral testosterone can cause this.  Measure LFTs when administering oral therapy
  18. Improvements
    Should see within 3-6 months
  19. Erectile dysfunction
    Can be caused by low testosterone but is more likely due to another problem.  Can give a phosphodiesterase inhibitor (Viagra) for that.
  20. Infertility treatment
    • For secondary hypogonadism only
    • GnRH pulsatile infusion
    • hCG- stimulates the Leydig cells to produce testosterone (necessary for sperm production)
    • hMG - stimulates the seminiferous tubules to produce sperm
Card Set
Male hypogonadism